JP3011099U - Blow-off valve for internal combustion engine - Google Patents

Abstract

(57) [Summary] [Purpose] To make it easy to adjust the operating range. A pressure sensor 21 electrically detects the pressure of a surge tank 7 provided behind the throttle valve 6. An electromagnetic valve 22 is provided to discharge and recirculate the air in the intake pipe 5. Each setting device 2 including a reference pressure value P, an offset amount ΔP, and a valve opening time T, including a variable resistor, etc.
It is set by 3, 24 and 25. The control device 26 controls the solenoid valve 22 when the pressure detection value D reaches the valve operating pressure value (P−ΔP) for the first time after reaching the reference pressure value P.
Is opened for a valve opening time T. If the pressure detection value D reaches the reference pressure value P before the valve opening time T elapses, the valve is closed without waiting for the valve opening time T elapse. The pressure setter 23 and the time setter 25 are attached at positions where setting operation can be performed from the driver's seat.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a blow-off valve for an internal combustion engine, and more particularly to a blow-off valve for an internal combustion engine that can control the opening and closing of the valve by using an electric signal.

[0002]

[Prior art]

 A technique for forcibly supplying air to an engine using a supercharger in order to improve the output of the internal combustion engine is widely known. Usually, the turbine of the supercharger is rotated by the exhaust gas of the engine and pressurized air is sent. In an internal combustion engine using such a supercharger, air compressed by the turbine is sent into the engine while the throttle is open to rotate the engine at high speed, and it is possible to obtain high output. But if you close the throttle, you'll have problems. That is, even if the accelerator pedal is released and the throttle is closed, the turbine of the supercharger continues to rotate due to inertial force, and pressurized air is still sent in for a while. Since the throttle valve is already closed, pressurized air that has lost its place will flow back to the turbocharger side. Such a reverse flow of the compressed air imposes an excessive load on the turbine blades, which is a factor of impairing the durability of the turbine.

A blow-off valve is used to solve such a problem. That is, a control valve is provided in the path from the supercharger to the throttle valve, and normally this control valve is closed, but when the throttle is closed, this control valve is opened and The air that tries to flow back to the supercharger side is discharged. Conventionally, generally used blow-off valves are diaphragm type and piston type. The diaphragm type sucks the diaphragm by the negative pressure of the surge tank located behind the throttle valve and opens the valve.The piston type opens the valve by operating the piston by the negative pressure of the surge tank. It is a thing.

[0004]

[Problems to be solved by the device]

 The conventional blow-off valve described above has a problem that it is difficult to adjust the operating region. In other words, both the diaphragm type and the piston type use valves that operate mechanically, so the operation of opening the valve when the negative pressure on the surge tank side reaches The area must be set by mechanical adjustment means such as spring adjustment. Moreover, since the control valve to be adjusted is installed in the engine room, when adjustment is necessary, it is necessary to open the engine room and adjust the spring etc. with a tool. Generally, the optimum operating range of the blow-off valve depends on the engine condition, the driving ability of the driver, the environment of the road, etc., and it is desirable to change the setting each time. However, the conventional mechanical blow-off valve had a problem that it was very difficult to use because it was necessary to open the engine room and adjust the spring etc. each time the operating range was reset.

Therefore, an object of the present invention is to provide a blow-off valve for an internal combustion engine that can easily adjust the operating range.

[0006]

[Means for Solving the Problems]

 (1) A first aspect of the present invention is a blow-off valve used in an internal combustion engine having a supercharger for discharging air flowing back to the supercharger when the throttle is closed. A pressure sensor that takes out the pressure of the surge tank provided between the engine and the electric detection signal, and opens and closes based on the electric control signal.In the open state, in the path from the supercharger to the throttle valve. And a control signal that has a function to discharge air, and a control signal to instruct that the valve be opened for a specified time and the air is discharged when the pressure value indicated by the detection signal obtained from the pressure sensor is below a specified value. And a control device for supplying the control valve to the control valve.

(2) A second aspect of the present invention is, in an internal combustion engine having a supercharger, a blow-off valve used for discharging air flowing back to the supercharger when the throttle is closed, A pressure sensor that takes out the pressure of the surge tank provided between the throttle valve and the engine as an electrical detection signal, and opens and closes based on the electrical control signal.In the open state, the turbocharger changes to the throttle valve. A control valve having a function of discharging the air in the route, a pressure setter for setting a predetermined reference pressure value P, an offset amount setter for setting a predetermined offset amount ΔP related to pressure, and a predetermined valve opening time. After the pressure detection value indicated by the detection signal obtained from the time setter that sets T and the pressure sensor reaches the reference pressure value P, the valve operating pressure value (P-Δ When reaching the), the control signal should only open T between time control valve valve opening, in which a control device controls the opening and closing giving the control valve, the provided.

(3) A third aspect of the present invention is the blow-off valve for an internal combustion engine according to the second aspect, wherein the pressure sensor is provided before the valve opening time T elapses after the control valve is opened. When the pressure detection value indicated by the detection signal obtained from the control signal reaches the reference pressure value P, the control signal to the control valve should be closed without waiting for the valve opening time T to elapse. Is given.

(4) According to a fourth aspect of the present invention, in the blow-off valve for an internal combustion engine according to the above-mentioned second or third aspect, the pressure setting device and the time setting device can be set and operated from the interior of the vehicle. It is configured in this way.

[0010]

[Work]

 The blow-off valve for an internal combustion engine according to the present invention can be called an electronic blow-off valve, as opposed to a conventional mechanical blow-off valve. The pressure of the surge tank is detected as an electric signal by the pressure sensor. A control valve that opens and closes in response to an electrical signal is used as a valve that discharges the air that flows back to the supercharger side. The control device operates to give a control signal to the control valve to open the valve for a predetermined time and discharge the pressurized air when the pressure value indicated by the electric signal given from the pressure sensor falls below a predetermined value. As a result, when the throttle valve is closed, the control valve will open and air will be exhausted. Since the control device operates based on the electric signal, its adjustment can be easily performed by using the circuit element.

Further, the reference pressure value P and the offset amount ΔP are set in advance, and after the pressure detection value indicated by the detection signal obtained from the pressure sensor reaches the reference pressure value P, the valve operating pressure value (P− If the control valve is opened when ΔP) is reached, the control valve will not operate while the pressure detection value is increasing, and the valve will be accidentally opened during acceleration with the throttle open. Can be prevented from opening. If the valve opening time T, which indicates the period in which the control valve is in the open state, can be set freely, adjustment with a higher degree of freedom becomes possible. In addition, if the detected pressure value reaches the reference pressure value P before the set valve opening time T elapses, if the valve is closed without waiting for the valve opening time T to elapse, acceleration will still occur. It can prevent the valve from opening inside.

Further, if a pressure setter and a time setter are provided inside the vehicle so that the reference pressure value P and the valve opening time T can be set from the inside of the vehicle, the driver can open the engine room. , It becomes possible to adjust the operating area of the blow-off valve.

[0013]

【Example】

 Hereinafter, the present invention will be described in detail with reference to illustrated embodiments. FIG. 1 is a model diagram showing an intake / exhaust related portion of a general internal combustion engine and a block diagram showing a configuration of a blow-off valve according to the present invention attached to the internal combustion engine. First, the model diagram of the intake and exhaust related parts of the general internal combustion engine shown in the upper half of FIG. 1 will be described. The air taken in from the air cleaner 1 is taken into the intake pipe 3 via the air flow meter 2 and sent into the intake pipe 5 by the supercharger 4. Vaporized fuel is supplied to the intake pipe 5 from a fuel supply system (not shown), and a mixture of the vaporized fuel and air is taken into the surge tank 7 through the slot valve 6. The air-fuel mixture in the surge tank 7 is further supplied to the engine 9 via the intake pipe 8. In the cylinder of the engine 9, exhaust gas is generated by combustion of the air-fuel mixture. This exhaust gas is discharged to the muffler 11 through the exhaust pipe 10, but the turbine 4a of the supercharger 4 is rotated in the middle thereof. In this way, the force of the exhaust gas is used to rotate the turbine 4a, and the rotation of the turbine 4a forces the air in the intake pipe 3 into the intake pipe 5.

In FIG. 1, the path indicated by the solid arrow is the above-mentioned air path. While the throttle valve 6 is open and the engine 9 is being driven at a high output, the supercharger 4 can efficiently feed the pressurized air into the intake pipe 5. However, even if the throttle valve 6 is closed, the turbine 4a of the supercharger 4 continues to rotate with inertial force, so compressed air is still fed into the intake pipe 5. At this time, the throttle valve 6 is closed and only a small amount of air-fuel mixture necessary for idling flows into the surge tank 7 side. Therefore, the compressed air in the intake pipe 5 that has lost its place of travel is discharged from the supercharger. It will flow back to the 4 side. This backflowing air exerts a force to rotate the turbine 4a in the opposite direction, so that an excessive load is applied to the turbine 4a, impairing its durability and possibly causing damage. It

The blow-off valve is a valve for exhausting the compressed air in the intake pipe 5 to the outside when such a phenomenon occurs. As described above, the conventional blow-off valve is a mechanical valve such as a diaphragm type or a piston type, but the blow-off valve according to the present invention is an electric or electronic valve having the following configuration. Is.

The blow-off valve according to this embodiment is shown in the pressure sensor 21 provided in the surge tank 7, the control valve 22 provided on the side of the intake pipe 5, and the block diagram of the lower half of FIG. The pressure setting device 23, the offset amount setting device 24, the time setting device 25, and the control device 26 are provided. Here, the pressure sensor 21 and the control valve 22 are both provided at predetermined locations in the engine room, but the pressure setting device 23, the offset amount setting device 24, the time setting device 25, and the control device 26 are It is installed in the driver's seat inside the vehicle.

The pressure sensor 21 is a sensor having a function of taking out the pressure value inside the surge tank 7 as an electrical detection signal, and the detected pressure is transmitted to the control device 26 as a pressure detection value D. To be done. On the other hand, the control valve 22 is a so-called electromagnetic valve that opens and closes based on an electrical control signal, and has a function of discharging the air in the intake pipe 5 in the open state. In this embodiment, a recirculation pipe 22 a (shown by a broken line in the figure) is provided between the control valve 22 and the intake pipe 3, and the air discharged by the control valve 22 is returned to the intake pipe 3. The arrow shown by the broken line in the figure shows the return path of the air exhausted by the control valve 22. The opening / closing operation of the control valve 22 is controlled by a valve control signal C provided from the control device 26.

The pressure setter 23 is a setter having a function of setting a predetermined reference pressure value P, and the offset amount setter 24 is a setter having a function of setting a predetermined offset amount ΔP related to pressure. Is. The time setter 25 is a setter having a function of setting a predetermined valve opening time T. All of these setters are for setting parameters necessary for the control operation of the control device 26. In this embodiment, since the control device 26 is composed of circuit elements such as transistors, each setting device is composed of a variable resistor or a variable capacitor. Of course, the control device 26 can be configured by various logical circuits and CPUs. In that case, each setting device can be configured by a register or a memory.

The main control operation of the control device 26 is to control when the pressure detection value D obtained from the pressure sensor 21 reaches the reference pressure value P and then the valve operating pressure value (P−ΔP) for the first time. That is, the valve 22 is opened for the valve opening time T. The control operation of the control device 26 will be described below in detail with reference to the flowchart of FIG.

First, in step S1, the pressure detection value D and the reference pressure value P are compared. That is, the output value of the pressure sensor 21 and the set value in the pressure setter 23 are compared. Then, in the subsequent step S2, the process proceeds to step S3 only when D> P. In other words, the loop of steps S1 and S2 waits until the output value of the pressure sensor 21 exceeds the set value P. When D> P, the pressure detection value D and the pressure value (P-ΔP) are compared in step S3. Here, the pressure value (P-ΔP) is a value obtained by subtracting the offset amount ΔP set in the offset amount setting device 24 from the reference pressure value P set in the pressure setting device 23, and here, this pressure value. Will be referred to as the valve operating pressure value. Then, in the subsequent step S4, the process proceeds to step S5 only when D <P-ΔP. In other words, it waits by the loop of steps S3 and S4 until the output value of the pressure sensor 21 falls to the valve operating pressure value (P-ΔP).

In this way, when D <P-ΔP, the valve is opened in step S5. That is, the valve control signal C for opening the valve is given to the control valve 22. In this embodiment, as the control valve 22, an electromagnetic valve that is opened only when energized is used, so that energization of the control valve 22 is started in step S5. Then, in the subsequent step S6, it is determined whether or not the elapsed time after opening the valve (after energization) exceeds the valve opening time T. After the valve opening time T has elapsed, the valve is closed in step S7. That is, the valve control signal C for closing the valve is given to the control valve 22 (in this embodiment, the energization of the solenoid valve is stopped). On the other hand, when the valve opening time T has not elapsed, the pressure detection value D is compared with the reference pressure value P in step S8, and step S9 is executed only when D> P. The process proceeds to step S7 to close the valve. In other cases, the process returns to step S6 via step S9.

After all, after the valve is opened in step S5, basically, the process of keeping the valve in the open state for the valve opening time T 1 and then closing the valve is performed, but the valve opening time T elapses. Before that, if the pressure detection value D given from the pressure sensor 21 reaches the reference pressure value P, the valve is closed without waiting for the valve opening time T to elapse. Become.

It will be described with reference to the graph of FIG. 3 that the control operation by the control device 26 functions well as the operation of the blow-off valve. This graph shows changes in the detected pressure value D by the pressure sensor 21, with the horizontal axis representing the time axis and the vertical axis representing the pressure axis. Now, considering the case where the accelerator pedal is depressed and the throttle is gradually opened from time t1, the pressure detection value D further rises after passing the point a at time t2. If the accelerator pedal is held down to some extent, the pressure detection value D will be in a steady state. However, if the accelerator pedal is released and the throttle is closed, the pressure detection value D will suddenly drop, and after passing the point b at time t3, the idle It drops to the state. After point c at time t4, the accelerator pedal is stepped on again and the throttle is gradually opened after a while, but the pressure detection value D rises after passing points d and e, but the accelerator pedal is released again and the throttle is released. When closed, the pressure detection value D 1 drops via the point f. When the accelerator pedal is depressed again and the throttle is opened, the pressure detection value D rises after passing through the point g.

When driving an automobile, the opening / closing operation of the throttle as described above is repeated every time the gear is changed or the brake is operated. At this time, what kind of valve control the control device 26 performs will be examined along the flowchart of FIG. First, in the process of gradually opening the throttle from time t1 to t2, the loop of steps S1 and S2 is repeatedly executed. Then, after passing the point a at the time t2, D 2> P, so that the process proceeds to step S3. After that, the loop of steps S3 and S4 is repeatedly executed for a while, but when point b at time t3 is passed, D <P−ΔP holds, so the process proceeds to step S5, and the valve is opened. Become . When the point c is reached at time t4, the elapsed time after opening the valve becomes equal to the valve opening time T, the valve is closed in step S7, and the process returns to step S1. Eventually, the control valve 22 is opened and the compressed air in the intake pipe 5 is exhausted and recirculated only during the period from the time t3 to the time t4 (valve opening time T) shown by hatching in the lower time chart of FIG. It will be.

In short, the basic idea of control by the control device 26 is that the control valve 22 is opened when the pressure detection value D reaches a predetermined valve operating pressure value, and is opened for a predetermined valve opening time T. To maintain and then close. However, if the control valve 22 is unconditionally opened when the detected pressure value D reaches the valve operating pressure value, the valve opening operation will continue even if the detected pressure value D rises. It is done and it is a problem. For example, in the graph of FIG. 3, it is a correct control to perform the opening operation of the control valve 22 at the points b and f at which the detected pressure value D reaches the valve operating pressure value (P−ΔP). However, it is wrong to open the control valve 22 at the point d. Point d is a point in the middle of rotating the engine at a high output by opening the throttle. At this point, it is necessary to close the control valve 22 and take in a large amount of compressed air into the intake pipe 5.

After all, only when the pressure detection value D reaches the valve operating pressure value (P−ΔP) while decreasing, the control valve 22 is opened, and the pressure detection value D increases and the valve operating pressure value (P -ΔP) is reached, the control valve 22 must be kept closed. In view of this, in this embodiment, two set values are set, that is, the reference pressure value P and the valve operating pressure value (P−ΔP) that is smaller than the reference pressure value P by the offset amount ΔP, and the pressure detection value D is set to the reference pressure value P. When the valve operating pressure value (P-ΔP) is reached for the first time after reaching it, the control valve is opened. In the case of the example of FIG. 3, the point b is the point at which the pressure detection value D 1 reaches the valve operating pressure value (P−ΔP) for the first time after the reference pressure value P reaches the point P (point a). Is the point at which the valve operating pressure value (P−ΔP) is reached not the first time but the second time. Therefore, the operation of opening the control valve is performed at point b but not at point d.

The control operation after time t4 is almost the same. That is, when the throttle is gradually opened to pass the point d and then the point e, D> P, and thus the process proceeds to step S3. After that, the loop of steps S3 and S4 is repeatedly executed for a while, but when point f at time t6 is passed, D <P−ΔP holds, so the process proceeds to step S5, and the valve is opened. Become. However, this time, since the point g is reached at the time t7 when the elapsed time does not reach the valve opening time T, the valve is closed in step S7 through steps S8 and S9. Therefore, the valve is closed not at time t8 but at time t7, and the valve opening time is shorter than the valve opening time T. As described above, basically, the valve opening is performed only during the valve opening time T set in the time setter 25, but before the time T elapses, the pressure detection value D becomes equal to the reference pressure value P. One of the features of this embodiment is that the valve is closed at that point in the case where the temperature rises to 0. This is because the fact that the detected pressure value D rises up to the set pressure value P indicates that the throttle is being opened and the engine is in the state where a high output is required. In such cases, the control valve 22 must be closed immediately to prepare for the delivery of large volumes of compressed air to the engine.

As described above, it will be understood that if the control operation by the control device 26 is performed based on the flow chart shown in FIG. 2, optimum control of the blow-off valve becomes possible. The operating region of this control operation can be freely adjusted by changing the settings of the reference pressure value P, the offset amount ΔP, and the valve opening time T. As described above, since the pressure setting device 23, the offset amount setting device 24, and the time setting device 25 can be configured by a variable resistor, a variable capacitor, or a register or a memory, an adjustment knob or the like should be provided in the vehicle. If the setting operation for these setting devices can be performed from the inside of the vehicle, the driver can adjust the operation area while sitting in the driver's seat. Generally, once the offset amount ΔP has been set, it is not necessary to change the setting, but the reference pressure value P and the valve opening time T depend on the engine condition, the driving ability of the driver, the environment of the road, It is desirable to change the setting each time according to the situation. Therefore, it is preferable that at least the pressure setter 23 and the time setter 25 be capable of changing the set values immediately from the driver's seat.

The adjustment ranges of the reference pressure value P, the offset amount ΔP, and the valve opening time T may be appropriately determined according to the individual internal combustion engine. For reference, the adjustment range in this embodiment is described. If you leave, for reference pressure value ^{P, -0.3~ + 0.3kgf / c m} 2, the offset ΔP is, 0~ + 0.3kgf / cm ^2, for the valve opening time T, 0 to 2 seconds Is set as an adjustment range, and a variable resistor or variable capacitor is operated to set a predetermined value within this adjustment range.

Further, as the control valve 22 in this embodiment, the minimum operating pressure is 0 kgf / cm. ^Two , The maximum working pressure is 10kgf / cm^TwoWe used a commercially available electromagnetic fluid control valve of the standard. Therefore, the control valve 22 has a pressure in the intake pipe 5 of 0 kgf / cm.^TwoIn this case, the operation is possible and the pressure in the intake pipe 5 is 10 kgf / cm.^TwoUntil it exceeds, it operates normally without leaking. Such operating conditions are sufficient even when applied to a racing car.

In the conventional mechanical blow-off valve, it was difficult to set the optimum operating region because the operating region was adjusted by adjusting the tightness of the spring. That is, if the operating region is set to the low pressure side by tightening the spring weakly, the valve can be opened even if the pressure in the intake pipe 5 is low, but conversely when high supercharging is performed. There is a possibility of leaking without being able to bear the pressure. On the other hand, if the operating region is set to the high pressure side by tightly tightening the spring, the leak during high supercharging can be suppressed, but conversely the valve will open when the pressure in the intake pipe 5 is low. It's gone. The blow-off valve of the present embodiment, as described above, 0kgf ^/ cm 2 ~10kgf ^/ Because cm is an electromagnetic valve that can be applied to a wide pressure range of ^2, even if the pressure in the intake pipe 5 is 0 kgf / cm ² Even in this case, the opening operation can be sufficiently performed, and even when the pressure in the intake pipe 5 becomes 10 kgf / cm ² at the time of high supercharging, the normal operation without leak becomes possible.

[0032]

[Effect of device]

 As described above, according to the blow-off valve for an internal combustion engine of the present invention, the control valve that opens and closes by the electric signal is controlled based on the pressure value detected as the electric signal. It will be easy to do.

[Brief description of drawings]

FIG. 1 is a model diagram showing an intake / exhaust related portion of a general internal combustion engine and a block diagram showing a configuration of a blow-off valve according to the present invention attached to the internal combustion engine.

FIG. 2 is a flow chart showing a control operation of a blow-off valve according to the present invention.

FIG. 3 is a graph showing a specific control operation of the blow-off valve according to the present invention.

[Explanation of symbols]

 1 ... Air cleaner 2 ... Air flow meter 3 ... Intake pipe 4 ... Supercharger 4a ... Turbine 5 ... Intake pipe 6 ... Throttle valve 7 ... Surge tank 8 ... Intake pipe 9 ... Engine 10 ... Exhaust pipe 11 ... Muffler 21 ... Pressure sensor 22 Control valve 22a ... Return pipe 23 ... Pressure setting device 24 ... Offset amount setting device 25 ... Time setting device 26 ... Control device C ... Valve control signal D ... Pressure detection value P ... Reference pressure value ΔP ... Offset amount T ... Valve open time

Claims (4)

[Scope of utility model registration request] 1. A blow-off valve used in an internal combustion engine equipped with a supercharger for discharging air flowing back to the supercharger when the throttle is closed, the blow-off valve being provided between the throttle valve and the engine. A pressure sensor that takes out the pressure of the surge tank provided as an electrical detection signal, and opens and closes based on an electrical control signal. In the open state, air in the path from the supercharger to the throttle valve is discharged. A control valve having a function, and a control signal for instructing that the valve is opened for a predetermined time to discharge air when the pressure value indicated by the detection signal obtained from the pressure sensor becomes a predetermined value or less. A blow-off valve for an internal combustion engine, comprising: 2. A blow-off valve used in an internal combustion engine equipped with a supercharger for discharging air flowing back to the supercharger when the throttle is closed, the blow-off valve being provided between the throttle valve and the engine. A pressure sensor that takes out the pressure of the surge tank provided as an electrical detection signal, and opens and closes based on an electrical control signal. In the open state, air in the path from the supercharger to the throttle valve is discharged. A control valve having a function, a pressure setter for setting a predetermined reference pressure value P, an offset amount setter for setting a predetermined offset amount ΔP related to pressure, and a time setter for setting a predetermined valve opening time T. When the pressure detection value indicated by the detection signal obtained from the pressure sensor reaches the valve pressure value (P−ΔP) for the first time after reaching the reference pressure value P. Blowoff valve for an internal combustion engine, characterized in that it comprises a control device which controls the opening and closing the control valve the control signal should only open the valve opening time T, given to the control valve. 3. The blow-off valve for an internal combustion engine according to claim 2, wherein a pressure detection value indicated by a detection signal obtained from the pressure sensor is used as a reference before the valve opening time T elapses after the control valve is opened. When the pressure value P is reached, the control device gives the control valve a control signal for closing the valve without waiting for the valve opening time T to elapse. Blow-off valve for. 4. The blow-off valve for an internal combustion engine according to claim 2 or 3, characterized in that the pressure setting device and the time setting device are configured so that they can be set and operated from the interior of the vehicle. Blow-off valve for internal combustion engine.